Patients who died because of MTC had a median age of 61 years (range 21-84) and were at stages III-IV in all cases; deaths occurred in 18% of sporadic MTC, 6% of MEN2a and 66.7% of MEN2b patients.
We also examined the sensitivity of RET (M918T), a RET mutation prevalent in aggressive multiple endocrine neoplasia type 2B, to these TKIs in the context of BaF3/KR cells.
For example, the detection of a mutated <i>RET</i> allele in family members at risk for inheriting MEN2A or MEN2B signaled that they would develop MTC, and possibly other components of the syndromes.
This family of 11 individuals with familial MTC type of MEN 2A syndrome demonstrated the moderate risk RETp.Val804Met (protein valine at residue 804 replaced by methionine) genetic mutation, with 2 of the relatives presenting with dermal hyperneury, cutaneous lesions classically described in MEN 2B syndrome, and 1 relative also showing multiple sclerotic fibromas, a cutaneous manifestation of PTEN (phosphatase and tensin homologue) hamartoma-tumor syndrome.
Generation of an induced pluripotent stem cell line from a patient with hereditary multiple endocrine neoplasia 2B (MEN2B) syndrome with "highest risk" RET mutation.
Rarely, patients present with typical physical features of MEN2B but without associated endocrinopathies (medullary thyroid carcinoma or pheochromocytoma) or a RET gene mutation; this clinical presentation is thought to represent a distinct condition termed 'pure mucosal neuroma syndrome'.
The objectives of this study are to describe the rare M918VRET mutation discovered in 8 MTC kindreds from Brazil lacking the MEN 2B phenotype classically observed in M918T patients and to investigate the presence of a founder effect for this germline mutation.
The MEN2A and MEN2B syndromes are due to activating mutations in the proto-oncogene RET (Rearranged in Transfection) and are characterized by different phenotypic features of the affected patients.
These autosomal dominant conditions occur in four types: MEN1 due to inactivating MEN1 mutations; MEN2A and MEN2B (MEN3) due to activating mutations of RET and MEN4 due to inactivating cyclin-dependent kinase inhibitor 1B (CDKN1B) mutations.
Forty-four MEN 2B patients carrying inherited (3 patients) and de novo (41 patients) M918TRET mutations were examined for signs and symptoms prompting MEN 2B.
Since RET function in mouse spermatogonial stem cells has been extensively studied, we are able to suggest that the MEN2B mutation provides a selective advantage by altering the PI3K/AKT and SFK signaling pathways.
We compared two oncogenic RET mutants, associated with MEN 2A (2ARET) or MEN 2B (2BRET) disease subtypes, that are predicted to have distinct downstream target genes.
Using a proteomic-multiplexed analysis of the phosphotyrosine signaling together with antibody-based validation techniques, we identified several candidate molecules for RET (rearranged during transfection) tyrosine kinase receptor carrying mutations responsible for the multiple endocrine neoplasia type 2A and 2B (MEN2A and MEN2B) syndromes in two human medullary thyroid carcinoma (MTC) cell lines, TT and MZ-CRC-1, which express the RET-MEN2A and RET-MEN2B oncoproteins, respectively.
More than 90% of M918T carriers with multiple endocrine neoplasia type 2B (MEN 2B) harbor de novo mutations in the REarranged during Transfection (RET) protooncogene.
Although there were no syndromic features or a positive family history, mutation analysis of the RET proto-oncogene showed a de novo germline Met918Thr mutation in both patients, confirming the diagnosis of multiple endocrine neoplasia type 2B (MEN 2B).
In multiple endocrine neoplasia 2B (MEN-2B) patients expressing RET(M918T), nuclear enrichment of STAT3 and elevated expression of CXCR4 was detected in metastatic thyroid C-cell carcinoma in the liver.